The Human Microbiome:

Exploring the microscopic inhabitants of our bodies

​As children, we learn to wash our hands as a way of warding off germs. And that’s good advice. What we don’t learn, however, is that many of these germs, or microbes, are good for us; that not only are they beneficial but also essential for optimum health and survival.

These microbes — bacteria, viruses, fungi and parasites — live on and within the human body, making up the human microbiome. It’s an area of research that scientists have only recently begun to explore.

These collections of single-cell and multicellular organisms and viruses — there are more than ten thousand different types — exist in specific microbiome communities on or in different parts of the body, including the eyes, nose, skin, mouth, lungs, stomach, colon and genitals.

The bad microbes — pathogens — cause disease. But the good microbes play important roles in everything from immune function to nutrition. For example, good bacteria help our bodies digest food and they produce essential vitamins in the intestinal tract, including Vitamin K and biotin.

“You can’t survive without the microbes on and in your body. They protect you. They create barriers against infection, and compete against pathogens,” said Dr. Sarah Highlander, the new Research Professor and Director of TGen’s Clinical Microbiome Services Center, located in Flagstaff at TGen’s Pathogen and Microbiome Division, or TGen North.

By focusing on the human microbiome, this new effort will enhance TGen’s position as a leading center for genomic analysis by including the ability to examine the impact of the microbiome on human health. This can range from: gastrointestinal disorders, such as irritable bowel disease; to skin problems, such as dermatitis; to mental disorders like autism spectrum.

“There are completely different compositions of organisms — communities — at different body sites. If you’re healthy, these microbial communities are doing good things for you,” said Dr. Highlander, whose new center will support the investigations of hundreds of physicians and researchers at TGen and City of Hope.

Even some viruses, which once were thought of only as invaders that make people sick, are now considered integral parts of the human microbiome and may be part of the human defense system.

Microbiomes are not limited to people, or even animals. While the new Clinical Microbiome Services Center will help investigate specific problems related to many serious human diseases, such as diabetes and cancer, it also will address the health needs of animals and microbes found the environment, such as in soil and water.

“Having a clinical services center dedicated to the microbiome will help ensure that we provide comprehensive clinical information to physicians and researchers that will in turn benefit patients,” said Dr. David Engelthaler, Director of TGen North.

“It also will allow us to better support our internal and external microbiome research needs in this growing area of human, veterinary and environmental health sciences,” he said. “Animals, the environment and humans are in constant contact and flux. So, the study of all of these systems is critical to the TGen North concept of ‘One Health’.”

An area of investigation that Dr. Highlander predicts will have a huge impact on health is in the realm of “bacteriotherapy,” in which a specific organism, or a set of organisms, may have a specific therapeutic role, such as response to chemotherapy, as has been shown in limited proof-of-principle studies.

“The probiotics that we buy at the grocery story are like shooting a shotgun, perhaps an empty one. We don’t know what they’re doing or if they are effective. In the near future, we expect there will be specific organisms, or microbial metabolites, that people will be able to take as targeted therapeutics. They will have specific beneficial effects against specific diseases,” she said.

“I’m really excited to be in a position at TGen where I think we now, using the human microbiome, can have a significant impact on human health,” Dr. Highlander said.

Leading The Way

Dr. Sarah Highlander, an expert in medical microbiology and the human microbiome, is the new Research Professor and Director of TGen’s Clinical Microbiome Services Center.

Dr. Highlander most recently was a Professor of Genomic Medicine at the J. Craig Venter Institute in La Jolla, Calif., where she worked for three years on microbiome projects that ranged from travelers’ diarrhea to antibiotic resistance transmission to pediatric tooth decay.

Prior that she spent nearly 24 years at the Baylor College of Medicine in Houston. As an Associate Professor and Graduate Program Director in the Department of Molecular Virology and Microbiology, she taught and mentored budding doctors and doctoral students, in addition to her research responsibilities. Dr. Highlander also was an Adjunct Associate Professor in the Human Genome Sequencing Center at Baylor, where from 2007 to 2014 she was a Principal Investigator on the National Institutes of Health-sponsored Human Microbiome Project.

Dr. Highlander holds more than a dozen patents, is the author of more than 70 peer-reviewed publications, numerous book chapters, and has helped secure more than $16 million in federal grant funding.